Dry cleaning apparatus



2 Sheets-Sheet 1 Filed July 31, 1965 0 O O 0 O O O O 0 INVENTOR. Dal/[dPa /z United States Patent 3,203,209 DRY CLEANING APPARATUS David R.Paulick, Dayton, Ohio, assignor to General Motors Corporation, Detroit,Mich., a corporation of Delaware Filed July 31, 1963, Scr. No. 299,049 7Claims. (Cl. 682tl7) This invention relates to a dry cleaning apparatusand more particularly to a controlled water injection system for a drycleaner having an electronic relative humidity sensing arrangement.

The proper operation of an effective dry cleaning system requires thatall soil, both water soluble and solvent soluble, be removed from thegarments being cleaned. For this reason perchlorethylene and detergentare frequently combined in a water-solvent solution to perform thecleaning task, and it is essential that the water content or relativehumidity of the solution be maintained at a predetermined level in orderto optimize the efiectiveness of the detergent in removing water solublespots.

Accordingly, it is an object of this invention to provide an improvedsystem for sensing the relative humidity of a dry cleaning solution and,in response thereto, providing a controlled supply of water to thesolution in order to maintain the solution at a desired relativehumidity.

Another object of this invention is the provision for supplying make-upwater to the dry cleaning solution only during a clothes agitationcycle, thereby to assure homogeneous mixing of solvent and water.

It is a further object of this invention to provide in a dry cleaner anelectronic sensing system in combination with a venturi for sensing therelative humidity of a dry cleaning solution and then supplying make-upWater thereto.

A more specific object of this invention is the provision of a drycleaner having a substantially enclosed solvent reservoir in combinationwith a circulating air system for drying clothes after cleaning, saidcirculating air system serving to draw vapor from the solvent reservoirinto relative humidity sensing relationship with the electronic sensingsystem.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein a preferred embodiment of the present invention isclearly shown. a

In the drawings:

FIGURE 1 is a front sectional view, partly in elevation, of a drycleaning apparatus suitable for use with this invention; and

FIGURE 2 is an enlarged fragmentary schematic representation of theelectronic system for sensing and controlling the relative humidity of adry cleaning solvent solution.

Suitable for use with this invention and turning now to FIGURE 1, aunitary dry cleaning systernor apparatus of the replaceable filtercartridge type is ilustrated. The system includes an outer cabinet 10for partially enclosing a clothes cleaner or agitating apparatus 12and'a clothes dryer or drying apparatus 14. Note that the clothes dryer14 is elevated above the floor to provide for a filter compartment 16therebelow. The clothes cleaner 12 has a top access door 18 which ispivotally openable for inserting and removing fabrics from the cleaner.

The clothes dryer 14 has a front access door 20 which faces the washeraccess door 18 adjacent one side thereof. This arrangement places theaccess doors 18 and 20 in a confined area defined by a top wall 22 and aside wall 24 of the dry cleaning cabinet 10a perforate grille 26 at therear of the confined space operating to withdraw V 3,203,209 PatentedAug. 31, 1965 fumes from the area. The outlet or vent grille 26 isconnected to the atmosphere through an exhaust blower at the rear of thecabinet.

The cleaner or agitating apparatus 12 is shown com prised of an outercabinet 28 in the top wall of which is located the access door 18,hinged along a rear edge thereof. Within the washer cabinet 28, agenerally cylindrical, imperforate solvent container 30 is disposedwhich includes an access opening in axial alignment with the top accesslid 18 of the washer. The lower end of the solvent container 30 includesa drain opening 32 draining the solvent container from a lowermostportion thereof. A generally cylindrical spin tub or container 34 isrotatably supported in the solvent container and includes a plurality ofcircumferentially arranged outflow ports 35 around an upper portionthereof and a top access opening 36 which aligns with the door 18immediately above. Within the spin tub 34, an agitator 37 is adapted forvertical reciprocation. A motor-driven agitating and spinning mechanismis shown generally at 38 and is adapted to vertically reciprocate theagitator 37 when operated in one manner and to rotate or spin the tub 34when rotated in another manner.

The clothes dryer 14 is a conventional, single pass, circulating airdryer substantially like that taught in the patent to Whyte 2,843,945issued July 22, 1958. The dryer includes a horizontally rotatabletumbling drum or container 38 having a perforate rear wall 40 and afront access opening 42 in alignment with the dryer door 20. A dryingheater 44 is disposed adjacent the perforate rear wall 40 of thetumbling drum and is adapted to be energized for drying clothes withinthe tumbling drum. During operation of the heater 44 and rotation of thetumbling drum 38, air is circulated by a fan 46 connected with the drumaccess opening 42 by way of a front duct 48,, said front duct beingexhausted to atmosphere by the fan through an exhaust duct 50.

The solvent circulating system for a dry cleaning fluid orsolven-t,.such as perchlorethylene (a somewhat toxic dry cleaning fluid)or Valclene (a nontoxic dry cleaning fiuid made by Du Pont Corporationwhich is essentially Freon 113) will now be described with reference toFIGURE 1. The main components of the circulating system include a sumpor solvent reservoir 52 having a top wall 54 with an air vent andspill-over return 56, thereby to substantially enclose the solvent andits vapor. Immersed in the solvent is a cooling coil 57 through whichWater courses, said water being thermostatically controlled to maintainthe solvent at its best cleaning temperature. Refrigerated Water may beused if the domestic supply thereof is too warm. Above the sump top wall54 is a pump 58 which has its inlet connected through a solvent suctiondip tube 60 to the bottom of the sump 52. A filter 62 is adapted toreceive the output of the pump through a conduit 64 which connects tothe inlet 66 of the filter. The case of the filter 62 is positionedangularly in the filter compartment 16, such that a gravity drain 68extends through the sump wall 54 and includes a valve 70 manuallyopenable to substantially drain the filter of solvent when the drycleaning system is shut down. A solvent by-pass line 72 is provided atthe top of the filter case to bleed air from the case. Unfilteredsolvent passes through the by-pass line during operation of thefiltration system and returns to the solvent reservoir. I

At one end of the filter, an outlet fitting 74 connects by way of asolvent supply conduit 76 through a two-way or two-position valve 78 andsupply conduit 79 to the tub access opening 36a terminal portion 80overlying the top of the spin tub 34. The two-position valve 78 may becontrolled such as by a solenoid into a first position connecting thefilter outlet 74 to the spin tub 34 and a 3 second position connectingthe filter outlet to a sump return line 82. Completing the circulatingsystem is a conduit 84 which connects to the drain outlet 32 of thesolvent container 30. This conduit 84 enters the sump 52 by way of abutton trap 86, access to which is gained through a removable lidthereabove for cleaning.

The fluid circulation system operates as follows. The pump 58 draws drycleaning fluid or solvent from sump 52 through the dip tube 60. This drycleaning fluid, cleaned of large objects by the trap 86, is forcedthrough the conduit 64 to the filter 62 which is effective to removesmall solids, solubles and any loose carbon particles from the drycleaning fluid. After an initial period in which the two-position valve78 returns the solvent to the sump, the valve is actuated to dischargethe solvent from the filter by way of the conduit 76 and its end nozzle80 into the spin tub 34. When the level of dry cleaning fluid within thetub reaches the outflow ports 35, the dry cleaning fluid will continueto overflow into the solvent container 30 and will return by gravitythrough the conduit 84 to the sump 52. For additional details on thereplaceable cartridge type of dry cleaning system, reference may be hadto the copending application Serial No. 120,420, filed June 28, 1961,now Patent No. 3,110,170, and to the other applications referred totherein and assigned to the same assignee.

In the afor-egoing equipment a cleaning solution of perchlorethylene anddetergent will remove or dissolve most of the soil from the garmentsbeing cleaned, and water soluble spots not removable in dry cleaningsolvent alone can often be removed by spotting with water prior to drycleaning. Such prespotting requires a certain amount of skill and extratime on the part of the attendant. Thus, it appears that the presence ofwater in a dry cleaning solution is helpful in the removal of watersoluble spots and it is known that even an increase in detergentconcentration does not sufficiently increase the systems potential forspot removal unless accompanied by an increase in the relative humidity(R.H.) of the solvent, i.e., the water content of the cleaning solution.Moreover, carbon soil removal will also increase slightly with thesolvent solution at a higher RH. and linting on the clothes will bereduced.

On the other hand, an excess of water in the dry cleaning solution hassome disastrous side effects, such as severe wrinkling of the garmentsbeing cleaned, shrinkage, and higher redeposition of soil or graying ofthe garments.

The foregoing suggests that the proportion of water to solventmaintained in the dry cleaning system is critical and it is to improvedapparatus for sensing and controlling this proportion that thisinvention is directed.

General The electronic sensing system of this invention is comprisedgenerally of an electronic controller and magnetic amplifier 100, arelative humidity sensing element 102 and a sniffer box 104the sniiferbox operating off of the negative pressure in the exhaust duct 48 of theclothes dryer 14 to draw vapor from the top of the sump across theelement 102. The water injection system consists of a solenoid valve106, a manually operated water control valve 108, a water fount or catchbasin 110 exposed in the area of the vent grille 26 and a venturi 112.

Electronic sensing system 1 The controller 180 may be aMinneapolis-Honeywell R7088C versa-tran adjustable relative humiditycontroller or equivalent which consists of a bridge circuit in which thehumidity sensing element 102 is one leg of the bridge. With a change inthe humidity of the dry cleaning solution in the sump (the amount ofmoisture the vapor above the dry cleaning solution is holding comparedto what it could hold), the resistance of the sensing element 102changes, thereby unbalancing the bridge. This signal is amplified andused to activate a relay whose contact switch 114 closes to energize thesolenoid valve 106 in a water supply line 116 which is tapped into thesolvent cooling coil 57 as at 118.

The amplifier portion of the controller is energized through conductors120 Whenever the two-way valve 78 in the tub fill line 79 is energizedin its first position to condition the solvent supply conduit forcontinuous solvent supply during the clothes cleaning cycle. Thesolenoid water valve 106 is energizable only when the clothes agitationcircuit is energized, i.e., when the agitating and spinning mechanism 38is energized in a manner to vertically reciprocate the agitator 37.Thus, in order to add water to the dry cleaning solution, both thetwo-way valve 78 and the mechanism 38 (for agitate) have to beenergized. Such an arangement permits the add tion of water to thecontinuously supplied dry cleaning solution only during the agitatecycle of the dry cleaning apparatus. If the clothes were not beingagitated, a possibility would exist whereby droplets of free water wouldimpinge upon certain of the garments, giving rise to problems such asshrinkage and uneven cleaning. By agitating the clothes concurrentlywith the supply of water to the solvent, a thorough mixing occurs andall garments are subjected to a homogeneous dry cleaning solution.

The humidity sensing element 102 is made of two gold electrodes havingintermeshed legs embossed on one side of a plastic base. A humiditysensitive film of polyvinyl alcohol and lithium chloride is applied overthe gold grid. A suitable element of this type is Minneapolis-HoneywellsQ229-102O element.

The sensor element 102 is located inside the sniiter box 8 104 which isattached to the underside of the dryer exhaust duct 48 or any othernegative pressure area of the dryer air circulating system such as thefilter drying compartment taught more fully in copending applicationSerial No. 282,838, filed May 22, 1963, and assigned to the sameassignee. The negative pressure occurring inside the duct 48 drawsperchlorethylene vapors through the duct 126 from the solvent sump 52and, more particularly, from the vapor space above the level 128 of thesolvent. The suction of the fan 46 draws these vapors over the element102 and into the exhaust duct 51). It is the relative humidity of thevapors passing over the element 102 that are sensed by the controller100 and subsequently used to control all the admission of water to thecirculating dry cleaning solution.

Water injection system The water to be injected into the system is takenfrom the solvent cooling coil 57 as at 118 and the injection orentrainment is controlled by the solenoid valve 186 and the manual valve108. An air gap exists between the water supply 116 and the catch basinso that the droplets of water supplied are visible to the user of thedry cleaner. The venturi 112 in the tub fill line 79 creates a negativepressure which is used to draw the water from the catch basin 110 intothe tub fill line through an inlet tap 130 in the venturi. In operation,approximately one and onehalf to two and one half ounces of water areadded to the solvent each time a reduced relative humidity is sensed bythe element 102.

It should now be seen that an improved system has been provided forsensing relative humidity of dry cleaning solvent. The negative pressureavailable in the circulating air system of a dryer is used to draw vaporfrom the solvent sump over a sensing element of an electronic relativehumidity sensing system, thereby to signal a proper injection orentrainment of makeup water into the dry cleaning solvent. Then theentrainment of this water is eflected through the negative pressureavailable at a venturi in the tub fill line.

While the embodiment of the present invention as herein disclosedconstitutes a preferred form, it is to be understood that other formsmight be adopted.

What is claimed is as follows:

1. In combination,

(a) means forming a first container adapted to contain a dry cleaningsolvent such as perchlorethylene or the like for dry cleaning clothes,

(b) means forming a second container adapted to contain the clothesafter dry cleaning thereof,

(c) means including said second container for conveying a stream of airthrough said second container for drying the clothes therein,

(d) means forming a substantially closed sump means containing apredetermined level of dry cleaning solvent therein,

(e) means including a water cooling line in said sump means below saidpredetermined level for cooling said dry cleaning solvent,

(f) means including a solvent supply conduit connected in supplyrelationship to said first container for effecting the recirculation ofdry cleaning solvent between said sump means and said first container,

(g) mean-s for entraining water into the dry cleaning solvent beingsupplied to said first container including a venturi in said solventsupply conduit having a suction inlet and a catch basin attachedthereto, a water supply conduit having one end connected to said watercooling line and its other end connected in air gap, gravity flowrelationship to said catch basin, and valve means in said water supplyconduit openable for passing a regulated amount of water to said catchbasin for subsequent entrainment through said venturi into the sloventbeing supplied to said first container,

(h) and control means for controlling said valve means, said controlmeans including sensing duct means interconnecting the air streamconveying means and said sump means in a manner to draw therethrough astream of vapor from above said predetermined level of dry cleaningsolvent in said sump means for sampling the relative humidity of the drycleaning solvent in said sump means, means in relative humidity sensingrelationship to said stream of vapor for effecting a control signal inresponse to the relative humidity sensed, and means for processing saidcontrol signal in a manner to open said valve means when the relativehumidity of said streams of vapor is below a predetermined value.

2. The combination of claim 1 wherein said catch basin is in an exposedposition above said first container.

3. In combination,

(a) means forming a first container adapted to contain a dry cleaningsolvent such as perchlorethylene or the like for dry cleaning clothes,

(b) means forming a second container adapted to contain the clothesafter dry cleaning thereof,

(c) means including said second container for conveying a stream of airthrough said second container for drying the clothes therein,

(d) means forming a substantially closed sump means containing apredetermined level of dry cleaning solvent therein,

(e) means including a Water cooling line in said sump means below saidpredetermined level for cooling said dry cleaning solvent,

(f) means including a solvent supply conduit connected in supplyrelationship to said first container for elfecting the recirculation ofdry cleaning solvent between said sump means and said first container,

(g) means for supplying water to the dry cleaning solvent including awater supply conduit and valve means in said water supply conduitopenable for passing a regulated amount of water to the dry cleaningsolvent being supplied to said first container,

(h) and control means for controlling said valve means,

said control means including sensing duct means interconnecting the airstream conveying means and said sump means in a manner to drawtherethrough a stream of vapor from above said predetermined level ofdry cleaning solvent in said sump means for sampling the relativehumidity of the dry cleaning solvent in said sump means, means inrelative humidity sensing relationship to said stream of vapor foreffecting a control signal in response to the relative humidity sensed,and means for processing said control signal in a manner to open saidvalve means when the relative humidity of said stream of vapor is belowa predetermined value.

4. In combination,

(a) means forming a container adapted to contain a dry cleaning solventsuch as perchlorethylene or the like for dry cleaning clothes,

(b) means for conveying a stream of air over the clothes after drycleaning thereof for drying the clothes,

(0) means forming a substantially closed sump means containing apredetermined level of dry cleaning solvent therein,

(d) duct means interconnecting the air stream conveying means with thesump means in a manner to draw therethrough a stream of vapor from abovesaid predetermined level of dry cleaning solvent in said sump means forsampling the relative humidity of the dry cleaning solvent in said sumpmeans,

(e) means including a solvent supply conduit con nected in supplyrelationship to said container for effecting the circulation of drycleaning solvent between said sump means and said container,

(f) means for entraining water into the dry cleaning solvent beingsupplied to said container including a venturi in said solvent supplyconduit having a suction inlet, a water supply conduit having one endconnected to a supply of water and its other end connected to saidsuction inlet, and valve means in said water supply conduit openable forpassing a regulated amount of water to said suction inlet for subsequententrainment through said venturi into the dry cleaning solvent beingsupplied to said container,

(g) and control means responsive to the relative humidity of the streamof vapor in said duct means for controlling said valve means.

5. In combination,

(a) means forming a container adapted to contain a dry cleaning solventsuch as perchloroethylene or the like for dry cleaning clothes,

(b) means for conveying a stream of air over the clothes after drycleaning thereof for drying the clothes,

(c) means forming a substantially closed sump means containing apredetermined level of dry cleaning solvent therein usable in saidcontainer,

((1) duct means interconnecting the air stream conveying means with thesump means in a manner to draw therethrough a stream of vapor from abovesaid predetermined level of dry cleaning solvent in said sump means forsampling the relative humidity of the dry cleaning solvent in said sumpmeans,

(e) means for supplying water to the dry cleaning solvent before it isused in said container including valve means openable for passing aregulated amount of water to the dry cleaning solvent,

(f) and control means responsive to the relative humidity of the streamof vapor in said duct means for controlling said valve means.

6. In combination,

(a) means forming a container adapted to contain a dry cleaning solventsuch as perchlorethylene or the like for dry cleaning clothes therein,

(b) means energizable for agitating the clothes in said container,

(c) means forming a substantially closed sump means containing apredetermined levelof dry cleaning solvent therein usable in saidcontainer,

(d) duct means connected with the sump means in a manner to conveytherethrough a stream of vapor from above said predetermined level ofdry cleaning solvent in said sump means for sampling the relativehumidity of the dry cleaning solvent in said sump means,

(e) means for supplying Water to the dry cleaning solvent includingvalve means openable for passing a regulated amount of Water to the drycleaning solvent only when said agitating means is energized,

(f) and control means responsive to the relative humidity of the streamof vapor in said duct means and including means energizable in responseto the energization of said agitating means for controlling said valvemeans.

7. In combination,

(a) means forming a container adapted to contain a dry cleaning solventsuch as perchlorethylene or the like for dry cleaning clothes,

(b) means for conveying a stream of air for removing solvent fumesresulting from said dry cleaning,

(c) means forming a substantially closed sump means containing apredetermined level of dry cleaning solvent therein usable in saidcontainer,

(d) duct means interconnecting the air stream conveying means with thesump means in a manner to draw therethrough a stream of vapor from abovesaid predetermined level of dry cleaning solvent in said sump means forsampling the relative humidity of the dry cleaning solvent in said sumpmeans,

(e) means for supplying Water to the dry cleaning solvent before it isused in said container including means operable for passing a regulatedamount of Water to the dry cleaning solvent,

(f) and control means responsive to the relative humidity of the streamof vapor in said duct means for controlling said means for passingwater.

References Cited by the Examiner UNITED STATES PATENTS 2,967,084- 1/61Reitz 68207 X 3,066,519 12/ 62 Boswinkle et al 5818.1 X 3,093,442 6/63Brown et al. 68l3 X WALTER A. SCHEEL, Primary Examiner.

WILLIAM I. PRICE, Examiner.

7. IN COMBINATION, (A) MEANS FORMING A CONTAINER ADAPTED TO CONTAIN ADRY CLEANING SOLVENT SUCH A PERCHLORETHYLENE OR THE LIKE FOR DRYCLEANING CLOTHES, (B) MEANS FOR CONVEYING A STREAM OF AIR FOR REMOVINGSOLVENT FUMES RESULTING FROM SAID DRY CLEANING, (C) MEANS FORMING ASUBSTANTIALLY CLOSED SUMP MEANS CONTAINING A PREDETERMINED LEVEL OF DRYCLEANING SOLVENT THEREIN USABLE IN SAID CONTAINER, (D) DUCT MEANSINTERCONNECTING THE AIR STREAM CONVEYING MEANS WITH THE SUMP MEANS IN AMANNER TO DRAW THERETHROUGH A STREAM OF VAPOR FROM ABOVE SAIDPREDETERMINED LEVEL OF DRY CLEANING SOLVENT IN SAID SUMP MEANS FORSAMPLING THE RELATIVE HUMIDITY OF THE DRY CLEANING SOLVENT IN SAID SUMPMEANS, (E) MEANS FOR SUPPLYING WATER TO THE DRY CLEANING SOLVENT BEFOREIT IS USED IN SAID CONTAINER INCLUDING MEANS OPERABLE FOR PASSING AREGULATED AMOUNT OF WATER TO THE DRY CLEANING SOLVENT.